java - for循环中的空指针异常

Question

我尝试通过将数组放入 for 循环来从字符串数组中获取我不想要的字符串。

我尝试下面的代码，但我得到 java.lang.NullPointerException ，我不知道为什么。

感谢您的帮助。

String unWanted = new String[]{"","a","b","c"};

String[] temp = new String[unWanted.length-1];
int p = 0;
for (int k = 0; k < unWanted.length; k++){
    if(unWanted[k].equals("") == false)
    {
        temp[p] = unWanted[k];
        p++;
    }
}

Answer 1

这里唯一的错误是String数组声明

String[] unWanted = new String[]{"","a","b","c"};

Answer 2

temp长度为 3，但您在循环中的位置 4 处插入值。

Answer 3

首先改变这一行

String unWanted = new String[]{"","a","b","c"};

至

String[] unWanted = new String[]{"","a","b","c"};

Answer 4

它甚至在编译吗？

String unWanted = new String[]{"","a","b","c"};

改成

 String[] unWanted = new String[]{"","a","b","c"};

更改后，我的console. 它工作正常